The task force also recommends patients suspected of having high blood pressure be monitored at home continuously for 12 to 24 hours before doctors diagnose them or prescribe medication. A one-time measurement, members of the task force contend, may be tainted by temporary stress, be it driving, work or simply going to the doctor's office.

"There probably are some people who could use a lower dose than they're currently taking because they have lower blood pressures at home than in the office, and their doctor doesn't know about that," Dr. Mark Ebell, of the University of Georgia and a member of the task force, told NBC News. "We think an even bigger concern is under-diagnosis and under-treatment. There are a lot of people out there who have high blood pressure who don't know it or who have high blood pressure and it's not being adequately treated."

Blood pressure testing is generally done for people who appear healthy, because the condition does not always cause visible symptoms -- screening is the primary method for discovering the condition. The prevalence of the condition suggests people should be screened more often if they do not have it, and also should be screened more often while being treated.

Hypertension and high blood pressure affected 29.1 percent of adults in the United States between 2011 and 2012. The incidence of the condition increases with age, from 7.3 percent for people between the ages of 18 and 39, to 32.4 percent in people aged 40 to 59, and 65 percent in people older than 60.

Researchers on the task force report as many as 30 percent of patient blood pressure readings are higher than their normal pressure because of momentary stress, including that derived from going to the doctor's office. To counter this, the task force recommends patients wear arm cuffs that measure their blood pressure every 20 to 30 minutes in order to get a more realistic picture.